The invention relates to disconnect switches for use with the start or auxiliary winding of a single phase AC induction motor. The invention particularly relates to improvements in further reduced cost and part content over the circuitry shown in commonly owned U.S. Pat. Nos. 4,622,506, 4,658,195 and 4,670,697, incorporated by reference.
The present invention provides simplified comparator circuitry, with reduced part content. The invention also provides simplified main and auxiliary winding voltage detectors and power supply circuitry of reduced cost.